Jealousy is a complex emotion which arises in the context of a triangular relationship. It is provoked by the perceived nature and quality of relationship between two others within the triad and consists of fear of abandonment, anger and hostility, and sadness. In pathological jealousy, the emotion is based on the erroneous belief that a sexual partner is engaged in a relationship with another person, which is seen as threatening. In this talk, I will draw attention to the difference between jealousy and envy. I will use pathological jealousy as an example of a delusional disorder with a view to discussing a novel way of considering delusional disorders. Finally, I will use literature, specifically Shakespeare’s Othello & The Winter’s Tale, and Tolstoy’s Kreutzer Sonata to illustrate my points as well delving into the evolutionary basis of jealousy and its role in femicide, uxoricide, filicide, and familicide.